Pulling-jack.



w. sYLv PULLIN K.

Patented July 5, 1910.

2 SHEETS-SHEET 1.

PULLING JACK APPLIOA'IIOI rmzn M223, 1000.

Patented July 5, 1910.

! SHEETS-SHEET 2.

"Inventor WALTER SYLVESTER, OF TUNSTALL, ENGLAND.

PULLIN G-JACK.

Specification of Letters Patent.

Application filed September 23, 1909.

Patented July 5, 1910. Serial No. 519,189.

- 1n an object or objects.

11 some services, for example the drawing of pit props, it is desirable that the jack should be capable of being connected. closely to one of the resisting supports for which pur ose it has been roposed to form the hea of the jack with serrated means for preventing the ack and its securing chain or equivalent slipping down its anchor pro but such an arrangement has not prove satisfactory in ractlce.

The object o the resent invention is to provide an improve construction of head or arrangement whereby the necessity of employing serrated means for the prevention of slipping is avoided and whereby the loop of chain encircling the anchor rop is caused to bear against or embrace a ar er' ortiou of the prop than heretofore, the ea being such as not to interfere with the use of the jack by connection to the anchor rop or support through a hook as ordinari y. For th1s purpose, the construction or arrangement of the parts of the head is such that after the chain or equivalent has been passed around the anchor ro or the like and appropriately fastene t e pulling action of the jack on the said chain, due to its own weight, and also to the tightening up of the chain by the jack, will cause the arc of contact over which pressure is. exe'rted by the chain to be increased and the prop to be tightly embraced. The function aforesaid is ac iieved by so arranging thearts that, with the retractile movement of t e head of the jack from the prop or the like, the ends or portions of the chain or equivalent connected to the head are brought closer together.

Pulling jacks embodying the invention can be constructed in various forms. H

In the accompanying drawings, Figure 1 transversely between t e for is a side elevation and Fig. 2 a plan of an improved jack head according to the invention. Fig.3 is a plan illustrating amodification and Figs. 4 and 5 are res ectively a side elevation and plan of a furt er modification.

As shown in Figs. 1 and 2, the rack or pulling bar a of the jack has a swiveling and ifurcated head piece I) jointed thereto so that it can turn about a' longitudinal axis 0-0 and so formedthat a block d can work hinge fashion about a ivot in 6 extending iied limbs b of the head piece I) so that the two parts 6 and (1 form a universal joint with the rack bar. The said block (1 is formed with a gap or jaw 1, which, if intended to receive a chain,

'may be shaped in a known way and as shown in Fig. 1 so as to receive and securely hold a link or inks g of the chain 9 inserted sidewise therein. One end 9 of the chain is permanently fastened, as by a link i, to the pivot in e, referably by forming the block d wit a bi urcated portion 7' for its reception, and the other end of the chain is or may be provided with a hook is which can be used in the ordinary way, when required. As will be seen, with the arrangement described, when a com aratively short length of the chain 9 is loose y passed around a prop h, designed to serve as an anchor or support, and connected to the jaw f of the block d, the weight of the rack bar a will cause the block (1 and link i to turn toward each other and assume the relative positions shown in Fig. 2, so that the chain 9 will then tightly embrace a larger portion of the circumference of the prop it than before for the purpose hereinbefore explained.

In the modification shown in Fig. 3, a flat head iece s is attached swivel fashion to the rack ar a or equivalent jack portion, and has a bent or loop shaped yoke t bolted or otherwise secured thereto so that a shacklelike device results to which one end of the chain 9 is directly connected b a link a while another portion of the chain g can be directly connected thereto through a block rv shapedtoe'ngage one or more links of the chain in a similar manner to the block (5 shown in the exam )le described with reference to Figs. 1 and 2 of the drawings, the said block 41 working loosely on the yoke t,

the arrangement being such that the link u and the said block '0 will a )proach one another for the urpose hereinbefore explained upon retractile movement of the head 8 6 from the anchor prop or support It to which the chain 9 is connected. 1n some cases the head piece I), or s 15, may be formed on or be rigidly secured to the rack bar a or equivalent instead of being swiveled thereto, but the latter arrangement is preferred.

As a modification of the jack head shown in Figs. 1 and 2, the link i, in lieu of directly engaging the pivot pin e may, as shown in Figs. 4 and 5, be connected thereto by a shackle link w so that the bending stress on the said pin 0 is reduced the block (1 in this case, instead of being bifurcated, being formed with a solid tail piece (Z disposed between the limbs of the shackle link '11).

What I claim is:-

1. A pullin jack head comprising a head piece, a flexib e connector, means articulated to the head securing one end of the connector thereto and means also articulated'to the head for securing the connector at a point intermediate of its length to such head piece so that retractile movement of the head piece from a support around which the flexible connector is passed, will bring the securing points of the connector closer together.

2. In a 1pulling jack adapted to be secured to an anc 101' ro by an encirclin flexible connector, a 'li ea piece for attac ing the flexible connector at-one end to the head piece, and a device also articulated to the head piece for attaching the flexible connector, intermediate of its length to the head piece and adapted to-increase'the arc of contact of th'. flexible connector around the prop with retractile movement of the jack.

3. A pulling jack head comprising a head piece, a device hinged to the mad piece for permanently securing one .end of a flexible connector thereto and a block also working hinge fashion u on the head piece and to which the flexib e connector can be secured at any desired point in its length.

4. A pulling jack head comprising a bifurcated head piece, a pivot pin extending transversel between the forked limbs of the head piece, a block working hinge fashion about said pivot pin, means for securin a flexible connector to the ivot pinan means for securing the flexib e connector at another point in its length to said block.

5. A pulling jack head comprising a swiveling and bifurcated head piece, apivot in extendin transversely between the for red limbs o the head plece, a block working hinge fashion about said pivot pin, means for securing aflexible connector to thepivot pin and means for securingtthe' flexible 'connector at another point'in its length'to said block.

6. A pulling jack head comprising a bifurcated head piece, a pivot pin extending transversely between the forked limbs of the head piece, a link for securing one end of a flexible connector to the pivot pin, a block having a ortion working hinge fashion about the pivot pin, and means for securing the flexible connector at an intermediate point in its length to said block.

7. A pullin jack head comprising a swiveling and bifurcated head iece, a pivot pin extending transversely etween the forked limbs of the head piece,.a link for securing one end of a flexible connector to the pivot pin, a block having a portion working hinge fashion about the pivot pin, and means for securing the flexible connector at an intermcdiate oint in its length to said block.

8. A pul ing jack comprising a retractile member, a head piece attached thereto, a chain having a hook .at one end, means for permanently attaching the othervend to the ead piece and a movable block mounted on the head piece to hold the chain at a point intermediate of its length and "bring the two points of connection of the chain closer together with retractile movement of the said ack member.

9. A pulling jack comprising a retractile member, a bifurcated head piece attached thereto, a chain having a hook at one end, a pivot-pin extending transversely between the forked limbs of the head piece, a block working hinge fashion about said pivot pin and having a jaw adapted to engage and hold the chain at a point intermediate of its length, and means for permanently attaching the other end of the chain to the pivot 10. A pulling jack comprising a retractile member, a swiveling and bifurcated head piece attached thereto, a chain having a hook at one end, a pivot pin extending transverselybetween the forked limbs of the head piece, a block working hinge fashion about said pivot (pin and having a jaw adapted to engage an hold the chain at a point intermediate of itsslength, and means for-permanently attaching the other end of the chain to the pivot pin.

11. A pullin jack comprising a retractile member, a 'bi urcated head piece attached thereto, a chain having a hook at one end, a pivot Cpin extending transversely between the forks limbs of the head piece, allink securing one end of the chain .to the pivot pin and a block having a portion workmg'hinge -fashion about the pivot-pin, and carrying a jaw adapted to receive a link intermediate of the length of the chain.

12. Apulling jack comprising a retractile member, a'swiveling and bifurcated head piece attached thereto, a chain fhavin a look at one end, a pivot pin extending transversely hetween the forked limbs of the head piece, a. link securing one end of the chain to the ivot in and a block having a portion wor ing iinge fashion about the pivot pin, and carrying a jaw adapted to reciaive a link intermediate of the length of the 0 1am.

I Signed at Burslem in the county of Stafford, England, this eleventh day of September 1909.

WALTER SYLVESTER. Witnesses:

PERCY SYLVESTER, JOHN H. COPESTAKE. 

